The "hack" I've seen the most frequently is buying a ticket that gets you in the priority lane in addition to a standard ticket so that one can go through minimal security wait times and then cancel the ticket in time for a refund.
Couldn't it get you in trouble? You'd have to check your bags under the standard ticket, but enter security under the premium one, and airport security might realize they have the same person on the flight twice.
I don't even know where to begin telling you how wrong you are.
While I often just pack a carry-on bag for weekend trips, anything more than 2-3 days I'm checking a bag. I don't have to pay for it, my bags get priority-tagged so I don't have a long wait at the other end, and I've had to reroute due to weather at a connection twice in the past year, both of which I knew about before arriving at the airport.
So of the arguments raised against checking bags in the replies further down, none of them actually apply, and checking a bag means less stuff for me to lug around in the airports.
The choice of whether to check a bag or not is, thus, dependent on the specific passenger, the specifics of their trip, etc., and it is irresponsible and flat-out wrong to suggest otherwise, especially in such a "this is right and everything else is wrong" fashion.
Does it count as "extraordinary circumstances" that I carry a Leatherman pretty much everywhere I go? Since we became scared of everything sharper than a thumb, I've had to check a bag if I want to travel with my multitool, which I don't think is terribly unreasonable.
I used to routinely fly with it on my person. I'd take it out of its sheath, put it in the basket for keys and change and such at the metal detector, and hand that to the uniformed agent standing there. I was never once challenged for this, or even looked askance at.
Checking bags adds a lot of time to your trip after the plane lands, you have to wait ages in many cases for the ground crews to unload and process your baggage. In addition the size for carry-on luggage is pretty large with a small amount of work you can pretty easily get all you need for a trip into the carry-on baggage.
Except for a few bad days, I generally don't wait long for my checked luggage. It's sometimes already there by the time I make it to the claim area. Finding overhead space can be a hassle and I much prefer boarding and unboarding without dragging a ton of stuff. And carry-on obviously limits the items you can bring along on a plane.
Your arguments are perfectly valid for some, but this is isn't a case of "this method is obviously right".
The size is basically the same everywhere because there's limited difference in the planes. EG American Airlines which I just flew has the limit of 56 x 36 x 23 cm. Big enough for a one week duffel easily.
